Libraries not found in ./configure step

[José Luis García Pallero]

Hello:

I'm trying to compile he Octave source code from the mercurial
repository and I obtain some warnings during the ./configure step.
First of all I obtain the message:

configure: error: BLAS and LAPACK libraries are required

This is strange, because I have the Lapack library installed in the
standard path. I need to add to the configure the option

--with-lapack=/usr/lib/lapack/liblapack.a

in order to avoid the error (I also add the BLAS path, but in my case
I use OpenBLAS, which I have installed in a non-standard directory)

Also I obtain the warnings:

configure: WARNING: UNEXPECTED: found nth_element working in g++
4.8.2.  Has it been patched on your system?
configure: WARNING: qrupdate not found.  The QR & Cholesky updating
functions will be slow.
configure: WARNING: ARPACK not found.  The eigs function will be disabled.
configure: WARNING: JAVA_HOME environment variable not initialized.
Auto-detection will proceed but is unreliable.

1- I don't understand the warnings about the g++ compiler
2- I have installed the QRUPDATE and ARPACK libraries in the standard
paths (/usr/lib/libqrupdate.a and /usr/lib/libarpack.a). I've tried to
pass the options --with-qrupdate-libdir=/usr/lib/
--with-arpack-libdir=/usr/lib/, but the warnings still appear
3- I don't understand also the warning about the JAVA_HOME

My system is a 64 bits Debian GNU/Linux, and I'm using the GCC environment 4.8.2

Best regards

-- 
*****************************************
José Luis García Pallero
address@hidden
(o<
/ / \
V_/_
Use Debian GNU/Linux and enjoy!
*****************************************